Presser-foot for zigzag stitching attachments



J. D. KARLE Sept. 26, 1933.

PRESSER FOOT FOR ZIGZAG STITGHING ATTACHMENTS Filed April 6, 1932 2 Sheets-Sheet l www J. D. KARLE sept. 26, w33.

PRESSER FOOT FOR ZIGZAG STITCHING ATTACHMENTS 'Filed April 6, 1932 2 Sheets-Sheet 2 sanita 5813323.11333 'ressens-roer non zrezao s'rrrcrnNe armeni/murs Y 4 claims. (c1. 11a- 160) This invention relates to v sewing machine presser-feet and more particularly to the type of presser-feet used with zigzag stitching attachments.` f

One of the objects of this invention is to provide a presser-foot for use with zigzag stitching attachments which will more eilectively shift the work laterally of the line of feed.

With the above and other objects inview, as will hereinafter appear, the invention consists in the devices, combinations andarrangements of parts hereinafter set orth and illustratedin the` accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings, Fig. 1 is a front elevation of a zigzag stitching attachment with my irnproved presser-foot attached, showing the needle in its highest position and' the position of the presser-foot and feed-dog at the completion ofA the right to left shifting movement.

Fig. 2 is an elevation showing the position of the presser-foot and feed-dog during theleit to right shifting movement." f f Fig. 3, is a plan view of the presser-foot.`

Fig. 4 is a front elevation of the presser-foot.

Fig. 5 isa side elevation and Fig. 6 is a disassembled perspective view of the presser-foot.

In the embodiment of this invention selected for illustration, 1 is the usual needle-bar bearing in which isjournaled ythe usual reciprocating needle-bar 2. Secured to the needle-bar 2 by the usual set-screw 3 is a needle-clamp 4 having a laterally extending arm 5 to which'is pivoted a pawl 6 having a stop 7 and constantly urged in a counterclockwise direction by the coil-spring 8. Secured to the usual presser-bar (not shown) is a kplate 9 having an upstanding inclined arm 10 and cross arm` 11. Pivoted to the upstanding arm 10 at the pivot point 12 is a swinging frame 13 having a depending portion 14 and inwardly extendf l:ing projections 15. rRotatably supported upon 45 the upstanding arm 10 is a ratchet-wheel 16 rigidlyconnected with a'cam-element 17 having a plurality of circumferentially spaced projections 18. Slidably mounted upon the laterally extending arms 11 of the plate 9 is a slide-bar 19 having 50 a depending portion 20 made integral therewith. The slide-bar 19 is provided`wi'th an adjustable eccentric stop 21 and a knurled headed adjustable stop-screw 22. In the operation of the attachment, shortly afterthe needle 2' is out of the Work the pawl 6 engages one of the teeth of the ratchet-wheel 16 and advances it one step. This causes one of the circumferentially spaced pro'- jections 18 on the cam-element 17 to contact one of the inwardly extending projections on the o the line of seam-formation. "The above described: C;

zigzag stitching attachment is substantially` the same as that forming the subject oi my cepending application Serial No. 578,262, filed December 1, 1931,'t0 which reference may be had for amore complete description. ,u The zigzag stitching attachment initiates the shifting movement of the'presser-foot while the usual four-motion feed-dog 35 is below the slotted throat-plate 36 and, when the adjustments are correct, completes the shifting movement just priory to the vpoint in the cycle when" the teeth of feed-dog 35 rise above the throat-plate 36. Due to improper adjustments and variations in the timing of the feed-dogs in different types of machines, it may happen that the lateral shifting movement of the presser-foot is not completed before the feed-dog teeth initially rise above the throat-plate. When presser-feet as heretofore constructed are used and this condition exists, the lateral shifting movement oi the work is retarded and in some instances completely stopped by the interference oi the feeddog teeth when they rise above the throat-plate. To overcome this difficulty, I have provided a presser-foot which rwill more effectively shift the work laterally of the line of seam-formation.

The presser-foot comprises a shank 24 secured by the cap-screw 23to the downwardly depending portion of the slide-bar 19. Made integral with the shank 24 is a sole-plate 25 having a smooth lower face 26, notches 27, and an elongated needle-aperture 28. Yieldingly secured vupon the sole-plate 25 is an inverted U-shaped member 29 having an elongated needle-aperture 31 andv depending work-engaging elements 30 provided with roughened portions or serrations A at U-shaped spring 32 is secured to the toe of the sole-plate 25 by means of the screws 33. The limbs 34 of .the flat spring 32 engage the upper surface of the member 29 and urge it downwardly. The iiatspring 32 is not as strong as the usual presser-bar spring, and therefore when the feed-dog 35 is below the throat-plate 36 the smooth lower face 25 of the 1w sole-plate 25 as well as the depending serrated work-engaging elements 30 contact the work 37 and hold it against the throat-plate 36. If the feed-dog should rise slightly above the throatplate before the lateral shifting movement of the presser-foot is complete, as shown in Figure 2, the sole-plate will be forced upward by the feed-dog. The limbs 34 of the fiat U-shaped spring 32 urge the inverted U-shaped member 29 and its depending work-engaging elements 30 downward thus maintaining engagement of the serrated faces 30 with the work 37. There is sufficient gripping action between the serrated depending working engaging elements 30 and the y throat-plate 36 to overcome the resistance between the feed-dog 35 and the smooth lower face 26 of the sole-plate and, therefore, the lateral shifting movement is not retarded or stopped when the feed-dog rises above the throat-plate before the lateral shifting movement is completed.

The teeth of the four motion feed-dog 35 continue to rise above the throat-plate 36 until the feed-dog reaches itsmaximum height, as shown in Figure l, before the forward work-feeding movement of the feed-dog 35 is begun. The distance the serrated faces 3G' of the work-engaging element 30 extends below the smooth lower face 26 of the sole-plate 25 is less than the distance the teeth of the feed-dog 35 extend above the throat-plate when the teeth of the feed-dog reach their maximum height. Therefore, the member 29 contacts the sole-plate 25 and moves upward therewith asthe teeth of the feed-dog 35 continue to rise above the throatplate, and consequently, when the teeth of thefeed-dog 35 reach their highest position above the throatplate the serrated faces 30' of the work-engaging element 30 are out of contact with the work. The feed-dog 35 then moves forward to advance the work.

It will be observed that the two arms 34 of the flat U-shaped spring 32 engages the inverted U-shaped member 29 on both sides of the elongated needle-aperture 3l and urge it downwardly. This construction equally distributes the pressure between the two work-engaging elements 30 when a plurality of thicknesses of the work are under one of the elements and a lesser number of thicknesses are under the other element.

From the foregoing description consideredin connection with the accompanying drawings, the

construction, manner of operation and several advantages of my improved presser-foot will be clearly and fully understood. It is apparent that such a device has a wide variety of uses, and it will be understood that the form, construction and arrangement of the several elements employed may be varied. Therefore, the privilege is reserved of resorting to all such legitimate changes therein as may be fairly embodied with- 1 in the spirit and scope of the appended claims.

Having thus set forth the nature of the invention, what I claim herein is:-

1. A presser-foot for zigzag stitching attachments comprising a shank, a sole-plate provided with an elongated needle-opening carried by said shank, and a member provided with an elongated needle-opening and depending Work-engaging'elements having serrations in their lower faces said member being yieldingly urged against said sole-plate by resilient means carried by one and engaging the other.

2. A presser-foot comprising a shank adapted to be secured to a zigzag stitching attachment, a sole-plate having a smooth lower face carried by said shank, an inverted U-shaped member provided at its ends with serrated work-engaging elements carried by said sole-plate, and spring means connecting said sole-plate and U-shaped member for urging said U-shaped member downwardly.

3. A presser-foot comprising a shank adapted to be secured to a zigzag stitching attachment, a sole-plate having a smooth lower face and provided With notches in its sides, and a member overlying said sole-plate having depending workengaging elements received in said notches and extending below the lower face of said sole-plate, said member being yieldingly urged against said sole-plate by resilient means carried by one and engaging the other.

4. In combination, a four-motion feed-dog, a presser-foot having a sole-plate with an elongated needle-aperture and a smooth lower face cooperating with said feed-dog to advance the work, an inverted U-shaped member provided at its ends with depending work-engaging elements having serrations in their work-engaging faces overlying said sole-plate, and a fiat U-shaped spring Xed to the toe of said presser-foot urging said U-shaped member downwardly.

JOHN D. KARLE. 

